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Finding the Fourth Proportional to 667.78, 999.73 and 389.29

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Solution

The fourth proportional to 667.78, 999.73 and 389.29 is: 582.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.78 : 999.73 = 389.29 : x
  2. Step 2: Convert to fraction form
    667.78/999.73 = 389.29/x
  3. Step 3: Cross multiply
    667.78x = 999.73 × 389.29
  4. Step 4: Simplify right side
    667.78x = 389,177.95
  5. Step 5: Solve for x
    x = 389,177.95/667.78
  6. Step 6: Final answer
    x = 582.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.